Abnormal blood test result: what happens at a GP review?

The email arrives, you open the report, and one number has a flag next to it. Most people search for it straight away, and the search rarely makes them feel better.

Here's what that flag means: one value fell outside the laboratory's reference range. It is a prompt for a doctor to look, and on its own it does not tell you what, if anything, is wrong.

If you'd rather talk it through than read about it, a private GP consultation at 117a Harley Street goes through your result alongside your history and examination, and agrees what happens next.

What does "abnormal" mean on a blood test report?

Every result on your report sits next to a reference range. That range is a statistical band, rather than a line between healthy and unhealthy, so landing just outside it is a reason to look more closely.

The band also moves. It varies between laboratories, and by your age, sex and, for some tests, the time of day or stage of your cycle when the sample was taken. That is why a single flagged value is common, and why it is the start of a conversation.

Why can't I just read the result myself?

You can see which number is high or low. What the number cannot tell you is why it moved, whether it matters clinically, or what should happen next.

Recent illness, medicines, supplements, hydration and, for some tests, what you last ate can all shift a result for a while. A GP puts the number next to your symptoms, history and examination findings, then decides whether it needs action, monitoring, a repeat test or a specialist referral.

What happens during a GP review?

Your GP goes through each flagged result, explains what it measures and why it may have come back outside range, and looks at it as part of your overall health. Because the consultation has no fixed time limit, there is time to go through more than one result properly.

Any prescription or referral letter written during the visit carries no separate clinic fee. Medicines from the pharmacy and any further tests are charged separately, and we explain any extra charge before it goes ahead.

What a GP review usually covers.

Is a flagged cholesterol result common?

More common than most patients expect. In a snapshot of Medical Express Clinic health MOT results completed between April and August 2026, 47% of screenings that included cholesterol markers had at least one high cholesterol-related finding. That is our own clinic figure rather than a national statistic.

A high cholesterol-related result on its own is not a diagnosis of cardiovascular disease. Results outside the range can be temporary, may need no treatment, or can be affected by medicines and supplements, which is exactly what the review looks at.

What if the result is urgent?

If a doctor or laboratory has told you a result needs urgent attention, follow that advice the same day rather than waiting for a routine review.

If new or worsening symptoms come on while you're waiting for a result, act on those first. For severe chest pain, breathlessness, sudden weakness or a suspected serious reaction, call 999 or go to A&E. For anything less severe but worrying, NHS 111 can advise, or you can book a same-day GP consultation.

Will I need another blood test?

Sometimes. It depends on what the original result was and how long ago the sample was taken, and your GP decides during the review. Some values are worth repeating on their own to confirm a real trend before acting. Others, read alongside your history, are clear enough to act on straight away.

If cholesterol or wider heart risk is the concern and a more detailed review is warranted, your GP may suggest a cardiology consultation with Prof Darrel Francis, Consultant Cardiologist (£250).

Does it matter where my original test was done?

Not for the review itself. It is the same £150 GP consultation whether you had your blood tests with us or elsewhere, including one of the popular blood tests at our sister clinic Blood London.

What helps most is the original report with the reference ranges shown next to each result. Bring that, and your GP can interpret it properly in one visit.